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-rw-r--r--decoder/tree_fragment.h243
1 files changed, 236 insertions, 7 deletions
diff --git a/decoder/tree_fragment.h b/decoder/tree_fragment.h
index 83cd1c1e..79722b5a 100644
--- a/decoder/tree_fragment.h
+++ b/decoder/tree_fragment.h
@@ -1,26 +1,44 @@
#ifndef TREE_FRAGMENT
#define TREE_FRAGMENT
+#include <deque>
#include <iostream>
#include <vector>
#include <string>
-
-#include "tdict.h"
+#include <cassert>
+#include <cstddef>
namespace cdec {
-static const unsigned NT_BIT = 0x40000000u;
-static const unsigned FRONTIER_BIT = 0x80000000u;
-static const unsigned ALL_MASK = 0x0FFFFFFFu;
+class BreadthFirstIterator;
+class DepthFirstIterator;
+
+static const unsigned LHS_BIT = 0x10000000u;
+static const unsigned RHS_BIT = 0x20000000u;
+static const unsigned FRONTIER_BIT = 0x40000000u;
+static const unsigned RESERVED_BIT = 0x80000000u;
+static const unsigned ALL_MASK = 0x0FFFFFFFu;
+
+inline bool IsNT(unsigned x) {
+ return (x & (LHS_BIT | RHS_BIT | FRONTIER_BIT));
+}
-inline bool IsInternalNT(unsigned x) {
- return (x & NT_BIT);
+inline bool IsLHS(unsigned x) {
+ return (x & LHS_BIT);
+}
+
+inline bool IsRHS(unsigned x) {
+ return (x & RHS_BIT);
}
inline bool IsFrontier(unsigned x) {
return (x & FRONTIER_BIT);
}
+inline bool IsTerminal(unsigned x) {
+ return (x & ALL_MASK) == x;
+}
+
struct TreeFragmentProduction {
TreeFragmentProduction() {}
TreeFragmentProduction(int nttype, const std::vector<unsigned>& r) : lhs(nttype), rhs(r) {}
@@ -36,6 +54,21 @@ class TreeFragment {
// (S (NP a (X b) c d) (VP (V foo) (NP (NN bar))))
explicit TreeFragment(const std::string& tree, bool allow_frontier_sites = false);
void DebugRec(unsigned cur, std::ostream* out) const;
+ typedef DepthFirstIterator iterator;
+ typedef ptrdiff_t difference_type;
+ typedef unsigned value_type;
+ typedef const unsigned * pointer;
+ typedef const unsigned & reference;
+
+ // default iterator is DFS
+ iterator begin() const;
+ iterator begin(unsigned node_idx) const;
+ iterator end() const;
+
+ BreadthFirstIterator bfs_begin() const;
+ BreadthFirstIterator bfs_begin(unsigned node_idx) const;
+ BreadthFirstIterator bfs_end() const;
+
private:
// cp is the character index in the tree
// np keeps track of the nodes (nonterminals) that have been built
@@ -49,6 +82,202 @@ class TreeFragment {
std::vector<TreeFragmentProduction> nodes;
};
+struct TFIState {
+ TFIState() : node(), rhspos(), state() {}
+ TFIState(unsigned n, int p, unsigned s) : node(n), rhspos(p), state(s) {}
+ bool operator==(const TFIState& o) const { return node == o.node && rhspos == o.rhspos && state == o.state; }
+ bool operator!=(const TFIState& o) const { return node != o.node || rhspos != o.rhspos || state != o.state; }
+ unsigned short node;
+ short rhspos;
+ unsigned char state;
+};
+
+class DepthFirstIterator : public std::iterator<std::forward_iterator_tag, unsigned> {
+ const TreeFragment* tf_;
+ std::deque<TFIState> q_;
+ unsigned sym;
+ public:
+ DepthFirstIterator() : tf_(), sym() {}
+ // used for begin
+ explicit DepthFirstIterator(const TreeFragment* tf, unsigned node_idx) : tf_(tf) {
+ q_.push_back(TFIState(node_idx, -1, 0));
+ Stage();
+ q_.back().state++;
+ }
+ // used for end
+ explicit DepthFirstIterator(const TreeFragment* tf) : tf_(tf) {}
+ const unsigned& operator*() const { return sym; }
+ const unsigned* operator->() const { return &sym; }
+ bool operator==(const DepthFirstIterator& other) const {
+ return (tf_ == other.tf_) && (q_ == other.q_);
+ }
+ bool operator!=(const DepthFirstIterator& other) const {
+ return (tf_ != other.tf_) || (q_ != other.q_);
+ }
+ unsigned node_idx() const { return q_.front().node; }
+ const DepthFirstIterator& operator++() {
+ TFIState& s = q_.back();
+ if (s.state == 0) {
+ Stage();
+ s.state++;
+ } else if (s.state == 1) {
+ const unsigned len = tf_->nodes[s.node].rhs.size();
+ s.rhspos++;
+ if (s.rhspos >= len) {
+ q_.pop_back();
+ while (!q_.empty()) {
+ TFIState& s = q_.back();
+ const unsigned len = tf_->nodes[s.node].rhs.size();
+ s.rhspos++;
+ if (s.rhspos < len) break;
+ q_.pop_back();
+ }
+ }
+ Stage();
+ }
+ return *this;
+ }
+ DepthFirstIterator operator++(int) {
+ DepthFirstIterator res = *this;
+ ++(*this);
+ return res;
+ }
+ // tell iterator not to explore the subtree rooted at sym
+ // should only be called once per NT symbol encountered
+ const DepthFirstIterator& truncate() {
+ assert(IsRHS(sym));
+ sym &= ALL_MASK;
+ sym |= FRONTIER_BIT;
+ q_.pop_back();
+ return *this;
+ }
+ unsigned child_node() const {
+ assert(IsRHS(sym));
+ return q_.back().node;
+ }
+ DepthFirstIterator remainder() const {
+ assert(IsRHS(sym));
+ return DepthFirstIterator(tf_, q_.back());
+ }
+ bool at_end() const {
+ return q_.empty();
+ }
+ private:
+ void Stage() {
+ if (q_.empty()) return;
+ const TFIState& s = q_.back();
+ if (s.state == 0) {
+ sym = (tf_->nodes[s.node].lhs & ALL_MASK) | LHS_BIT;
+ } else if (s.state == 1) {
+ sym = tf_->nodes[s.node].rhs[s.rhspos];
+ if (IsRHS(sym)) {
+ q_.push_back(TFIState(sym & ALL_MASK, -1, 0));
+ sym = tf_->nodes[sym & ALL_MASK].lhs | RHS_BIT;
+ }
+ }
+ }
+
+ // used by remainder
+ DepthFirstIterator(const TreeFragment* tf, const TFIState& s) : tf_(tf) {
+ q_.push_back(s);
+ Stage();
+ }
+};
+
+class BreadthFirstIterator : public std::iterator<std::forward_iterator_tag, unsigned> {
+ const TreeFragment* tf_;
+ std::deque<TFIState> q_;
+ unsigned sym;
+ public:
+ BreadthFirstIterator() : tf_(), sym() {}
+ // used for begin
+ explicit BreadthFirstIterator(const TreeFragment* tf, unsigned node_idx) : tf_(tf) {
+ q_.push_back(TFIState(node_idx, 0, 0));
+ Stage();
+ }
+ // used for end
+ explicit BreadthFirstIterator(const TreeFragment* tf) : tf_(tf) {}
+ const unsigned& operator*() const { return sym; }
+ const unsigned* operator->() const { return &sym; }
+ bool operator==(const BreadthFirstIterator& other) const {
+ return (tf_ == other.tf_) && (q_ == other.q_);
+ }
+ bool operator!=(const BreadthFirstIterator& other) const {
+ return (tf_ != other.tf_) || (q_ != other.q_);
+ }
+ unsigned node_idx() const { return q_.front().node; }
+ const BreadthFirstIterator& operator++() {
+ TFIState& s = q_.front();
+ if (s.state == 0) {
+ s.state++;
+ Stage();
+ } else {
+ const unsigned len = tf_->nodes[s.node].rhs.size();
+ s.rhspos++;
+ if (s.rhspos >= len) {
+ q_.pop_front();
+ Stage();
+ } else {
+ Stage();
+ }
+ }
+ return *this;
+ }
+ BreadthFirstIterator operator++(int) {
+ BreadthFirstIterator res = *this;
+ ++(*this);
+ return res;
+ }
+ // tell iterator not to explore the subtree rooted at sym
+ // should only be called once per NT symbol encountered
+ const BreadthFirstIterator& truncate() {
+ assert(IsRHS(sym));
+ sym &= ALL_MASK;
+ sym |= FRONTIER_BIT;
+ q_.pop_back();
+ return *this;
+ }
+ unsigned child_node() const {
+ assert(IsRHS(sym));
+ return q_.back().node;
+ }
+ BreadthFirstIterator remainder() const {
+ assert(IsRHS(sym));
+ return BreadthFirstIterator(tf_, q_.back());
+ }
+ bool at_end() const {
+ return q_.empty();
+ }
+ private:
+ void Stage() {
+ if (q_.empty()) return;
+ const TFIState& s = q_.front();
+ if (s.state == 0) {
+ sym = (tf_->nodes[s.node].lhs & ALL_MASK) | LHS_BIT;
+ } else {
+ sym = tf_->nodes[s.node].rhs[s.rhspos];
+ if (IsRHS(sym)) {
+ q_.push_back(TFIState(sym & ALL_MASK, 0, 0));
+ sym = tf_->nodes[sym & ALL_MASK].lhs | RHS_BIT;
+ }
+ }
+ }
+
+ // used by remainder
+ BreadthFirstIterator(const TreeFragment* tf, const TFIState& s) : tf_(tf) {
+ q_.push_back(s);
+ Stage();
+ }
+};
+
+inline TreeFragment::iterator TreeFragment::begin() const { return iterator(this, nodes.size() - 1); }
+inline TreeFragment::iterator TreeFragment::begin(unsigned node_idx) const { return iterator(this, node_idx); }
+inline TreeFragment::iterator TreeFragment::end() const { return iterator(this); }
+
+inline BreadthFirstIterator TreeFragment::bfs_begin() const { return BreadthFirstIterator(this, nodes.size() - 1); }
+inline BreadthFirstIterator TreeFragment::bfs_begin(unsigned node_idx) const { return BreadthFirstIterator(this, node_idx); }
+inline BreadthFirstIterator TreeFragment::bfs_end() const { return BreadthFirstIterator(this); }
+
inline std::ostream& operator<<(std::ostream& os, const TreeFragment& x) {
x.DebugRec(x.nodes.size() - 1, &os);
return os;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 18:33:53 +0000